Field of the Invention
Embodiments of the present invention provide an apparatus and a method for research and testing of small aquatic species, and particularly to an apparatus and method for various screening procedures of Danio rerio, commonly known as zebrafish.
Description of Related Art
Animals are used extensively in genetic research. Among other purposes and benefits, such genetic research helps scientists locate and understand the causes of various diseases and behaviors that manifest in humans. Many animals have enough genetic similarities to humans to make them good analogs for genetic testing, as they are easy to breed and there are lesser ethical considerations than performing genetic testing on humans. One such animal is the Danio rerio, commonly known as the zebrafish, which is a vertebrate like humans. Because of this similarity, it is likely that zebrafish have similar biological traits, including genes, developmental processes, anatomy, physiology, and behaviors.
Various screening processes are performed on zebrafish, such as genotyping and embryonic screening for mutant phenotypes. Currently, when DNA or embryos are being screened, the zebrafish are housed in individual tanks that range in size from about 0.8 liters to 2 liters. Such tanks are much larger than necessary. One liter can hold approximately 5-15 individual zebrafish. However, during the screening process, this volume of water is used to house either individuals or pairs of zebrafish only, which amounts to an extremely inefficient use of water and space. These tanks are commonly stored on housing racks. Because the size of each tank is so large compared to the number of zebrafish being housed in each tank, each rack is able to store only a relatively minimal amount of zebrafish. Therefore, more racks are required. This makes for a very inefficient testing set up, poor use of lab space and time consuming efforts in connection with transporting the zebrafish to and from the testing area.
In addition, due to this inefficient set up and storage method, often, the zebrafish in these tanks are kept off system where they are not adequately monitored. This may result in the water developing into poor condition, thereby becoming hazardous to the zebrafish. This may also result in unnecessary stress to the experimental animals.
Furthermore, microtiter plates are commonly used to store or house the samples/specimens extracted from the zebrafish during a screening process, particularly genotyping. A microtiter plate typically has 6, 24, 96, 384, or even 1536 sample wells arranged in a ‘2:3’ rectangular matrix. Therefore, it is critical to the research that the tanks are properly labeled so the samples/specimens extracted from the zebrafish and stored in a specific well of a microtiter plate are matched with the appropriate zebrafish from which it was extracted. This requires an extremely painstaking and time-consuming process in which researchers, many of whom are Ph.D.'s, must use up valuable research time in order to properly label each individual tank.
Moreover, the embryonic screening process, which is very commonly performed in laboratories, involves the breeding of hundreds of pairs of zebrafish every week. After the zebrafish breed and spawn, and the embryos are collected, the spawning zebrafish are placed in holding tanks while the embryos are screened for mutant phenotypes. If the embryos show interesting phenotypes, the pair that produced those embryos is retrieved and additional steps, including out-crossing and more pair-wise crossing, are taken to isolate the gene that was mutated.
In many cases, this process could take years to isolate the mutated gene. Due to the high volume of pairs of zebrafish that are bred each week, an excessive amount of water and storage space is required. Also, given the painstaking nature and potential lengthiness of the process, it is critical that items are properly labeled and records properly kept. Again, valuable research time is wasted labeling to try to minimize the risk of errors.
Therefore, a need exists for a versatile apparatus, system, and method for various types of testing of zebrafish in an efficient and effective manner.